Vehicle driving device

Abstract

In a vehicle designed so that a driven wheel is driven by uniting an output from an engine and an output from a Rankine cycle system to each other, an accelerator pedal and a throttle valve are connected electrically to each other by a DBW control unit. When an accelerator opening degree (θap) commanded by a driver is increased, a throttle opening degree (θth) is increased by a correcting amount (Δθth) more than a value proportional to the accelerator opening degree (θap), thereby compensating for an output shortage due to a response delay of the output from the Rankine cycle system. When the accelerator opening degree (θap) commanded by the driver is decreased, the throttle opening degree (θth) is decreased by the correcting amount (Δθth) more than the value proportional to the accelerator opening degree (θap), thereby compensating for an output excessiveness due to the response delay of the output from the Rankine cycle system.

1. A propelling system for a vehicle comprising an engine and a Rankine cycle system for converting heat energy of exhaust gas from the engine into mechanical energy to output the mechanical energy, so that a wheel is driven by a combined output from the engine and from the Rankine cycle system,
 wherein said propelling system includes a control means for controlling a throttle opening degree of the engine by correcting an accelerator opening degree commanded by a driver, and said control means controls the throttle opening degree of the engine, so that said combined output assumes a value corresponding to the accelerator opening degree, in order to compensate for a response delay of the output from the Rankine cycle system, and  
 wherein when an increase in the accelerator opening degree is commanded to be an increased value, the throttle opening degree is increased to a value that is larger by a correction amount than a value proportional to the increased value of the accelerator opening degree, whereas when a decrease in the accelerator opening degree is commanded to be a decreased value, the throttle opening degree is decreased to a value that is smaller by a correction amount than a value proportional to the decreased value of the accelerator opening degree.  
 
   
   
     2. A propelling system for a vehicle comprising a Rankine cycle system for converting heat energy of exhaust gas from an engine into mechanical energy to output the mechanical energy, so that a wheel is driven by a combined output from the engine and from the Rankine cycle system,
 wherein said propelling system includes control means for controlling a throttle opening degree of the engine by correcting an accelerator opening degree commanded by a driver, and said control means controls the throttle opening degree of the engine, so that said combined output assumes a value corresponding to the accelerator opening degree, in order to compensate for a response delay of the output from the Rankine cycle system, the control means calculating the throttle opening degree based on the accelerator opening degree, the temperature of the exhaust gas, an air fuel ratio, an engine rotational speed, an intake negative pressure and an injected fuel amount.  
 
   
   
     3. The propelling system according to  claim 2 , wherein the control means controls the operation of a throttle motor which drives a throttle valve based on the throttle opening degree. 
   
   
     4. The propelling system according to  claim 3 , wherein a first response delay due to an abatement of heat in an exhaust port is generated until the temperature and flow rate of the exhaust gas reach steady states when the output from the engine is changed. 
   
   
     5. The propelling system according to  claim 4 , wherein a second response delay due to heat transfer in a heat-transfer pipe is generated when the temperature and flow rate of the exhaust gas are changed. 
   
   
     6. The propelling system according to  claim 5 , wherein the control means controls the operation of the throttle motor based on the first and second response delays. 
   
   
     7. The propelling system according to  claim 3 , wherein the throttle motor includes an output shaft connected to the throttle valve so that the throttle motor is rotated about an axis of the output shaft and an accelerator pedal is connected to the throttle motor.